Other Medical Sciences Commons^™

Animal Carcinogenicity Studies: 1. Poor Human Predictivity, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

The regulation of human exposure to potentially carcinogenic chemicals constitutes society’s most important use of animal carcinogenicity data. Environmental contaminants of greatest concern within the USA are listed in the Environmental Protection Agency’s (EPA’s) Integrated Risk Information System (IRIS) chemicals database. However, of the 160 IRIS chemicals lacking even limited human exposure data but possessing animal data that had received a human carcinogenicity assessment by 1 January 2004, we found that in most cases (58.1%; 93/160), the EPA considered animal carcinogenicity data inadequate to support a classification of probable human carcinogen or non-carcinogen. For the 128 chemicals with human or …

Animal Carcinogenicity Studies: 2. Obstacles To Extrapolation Of Data To Humans, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

Due to limited human exposure data, risk classification and the consequent regulation of exposure to potential carcinogens has conventionally relied mainly upon animal tests. However, several investigations have revealed animal carcinogenicity data to be lacking in human predictivity. To investigate the reasons for this, we surveyed 160 chemicals possessing animal but not human exposure data within the US Environmental Protection Agency chemicals database, but which had received human carcinogenicity assessments by 1 January 2004. We discovered the use of a wide variety of species, with rodents predominating, and of a wide variety of routes of administration, and that there were …

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …

Cancerous Contradictions: The Mis-Regulation Of Human Carcinogens Based On Animal Data, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

The regulation of human exposures to potential carcinogens constitutes society’s most important use of animal carcinogenicity data. However, for environmental contaminants of greatest U.S. concern, we found that in most cases (58.1%; 93/160) the U.S. Environmental Protection Agency (EPA) considered the animal data inadequate to support a classification of probable human carcinogen or noncarcinogen.

The World Health Organisation’s International Agency for Research on Cancer (IARC) is a leading international authority on carcinogenicity assessments. For chemicals lacking human exposure data (the great majority), IARC classifications of identical chemicals were significantly more conservative than EPA classifications (p

Which Drugs Cause Cancer?, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Experimentation Collection

Animal tests yield misleading results.

Animal Models Of Head Trauma, Ibolja Cernak

Biomedicine and Animal Models in Research Collection

Animal models of traumatic brain injury (TBI) are used to elucidate primary and secondary sequelae underlying human head injury in an effort to identify potential neuroprotective therapies for developing and adult brains. The choice of experimental model depends upon both the research goal and underlying objectives. The intrinsic ability to study injuryinduced changes in behavior, physiology, metabolism, the blood/tissue interface, the blood brain barrier, and/or inflammatory- and immune-mediated responses, makes in vivo TBI models essential for neurotrauma research. Whereas human TBI is a highly complex multifactorial disorder, animal trauma models tend to replicate only single factors involved in the pathobiology …

Trials, Tribulations, And Trends In Tumor Modeling In Mice, Joann C. L. Schuh

Toxicology and Animal Models in Research Collection

Selection of mouse models of cancer is often based simply on availability of a mouse strain and a known compatible tumor. Frequently this results in use of tumor models long on history but short on homology and quality control. Other factors including genetics, sex, immunological status, method and site of tumor implantation, technical competence, biological activity of the tumor, protocol sequence and timing, and selection of endpoints interact to produce outcomes in tumor models. Common reliance on survival and tumor burden data in a single mouse model often skews expectations towards high remission and cure rates; a finding seldom duplicated …

Trials, Tribulations, And Trends In Tumor Modeling In Mice, Joann C. L. Schuh

Biomedicine and Animal Models in Research Collection

Selection of mouse models of cancer is often based simply on availability of a mouse strain and a known compatible tumor. Frequently this results in use of tumor models long on history but short on homology and quality control. Other factors including genetics, sex, immunological status, method and site of tumor implantation, technical competence, biological activity of the tumor, protocol sequence and timing, and selection of endpoints interact to produce outcomes in tumor models. Common reliance on survival and tumor burden data in a single mouse model often skews expectations towards high remission and cure rates; a finding seldom duplicated …

Renal Basolateral Transport Of Glucuronides And Other Organic Anions In Rat In Vitro Models, Sarah L. Miles

Theses, Dissertations and Capstones

Glucuronidation is a common Phase II biotransformation reaction that increases the hydrophilicity, and thus elimination, of toxins, xenobiotics, and endogenous compounds. Previous studies suggest that the kidney can secrete glucuronide conjugates, but the renal transport mechanisms for glucuronide secretion have not been determined. Based on the chemical nature of glucuronide metabolites, it is hypothesized that organic anion transporter (OAT) proteins along the basolateral membrane of the renal proximal tubule promote renal accumulation of glucuronide conjugates. The purpose of this study was to develop a rat renal proximal tubule model which demonstrates OAT activity and by which the contribution of OAT …

Compendium Of Chemical Carcinogens By Target Organ: Results Of Chronic Bioassays In Rats, Mice, Hamsters, Dogs, And Monkeys, Lois Swirsky Gold, Neela B. Manley, Thomas H. Sloane, Jerrold M. Ward

Toxicology and Animal Models in Research Collection

Acompendiumof carcinogenesi s bioassay results organized by target organ is presented for 738 chemicals that are carcinogenic in chronic-exposure , long-term bioassays in at least 1 species. This compendium is based primarily on experiments in rats or mice; results in hamsters, monkeys, and dogs are also reported. The compendium can be used to identify chemicals that induce tumors at particular sites and to determine whether target sites are the same for chemicals positive in more than 1 species. The source of information is the Carcinogeni c Potency Database (CPDB), which includes results of 6073 experiments on 1458 chemicals (positive or …

Research Fundamentals: V. The Use Of Laboratory Animal Models In Research, Brian J. O'Neil, Jeffrey A. Kline, Keith Burkhart, John Younger

Biomedicine and Animal Models in Research Collection

Animal research has provided important information about many aspects of the pathophysiology of human disease. Well-performed animal studies can determine the potential benefit of many proposed therapeutic interventions, and experimental results from animal studies have served as the basis for many landmark clinical trials. Many animal research models are described in the research literature, and choosing the appropriate model to answer a research question can be a daunting task. Even more challenging is developing a new model when none of the existing systems are relevant to the proposed question. This article was prepared by members of the SAEM Research Committee …

Assessment Of Side Effects Induced By Injection Of Different Adjuvant/Antigen Combinations In Rabbits And Mice, P.P.A.M. Leenaars, M. A. Koedam, P. W. Wester, V. Baumans, E. Claassen, C. F.M. Hendriksen

Biomedicine and Animal Models in Research Collection

We evaluated the side effects induced by injection of Freund's adjuvant (FA)and alternative adjuvants combined with different antigens. Rabbits and mice were injected subcutaneously, intramuscularly (rabbits) and intraperitoneally (mice)with different adjuvants (FA, Specol, RIBI,TiterMax, Montanide ISA50)in combination with several types of antigens (synthetic peptides, autoantigen, glycolipid, protein, mycoplasma or viruses). The effects of treatment on the animals' well-being were assessed by clinical and behavioural changes (POTand LABORASassays) and gross and histopathological changes. In rabbits, treatment did not appear to induce acute or prolonged pain and distress. Mice showed behavioural changes immediately after (predominantly secondary) immunization. Injection of several adjuvant/antigen mixtures …

Animal Organs In Humans: Uncalculated Risks And Unanswered Questions, Gillian R. Langley, Joyce D'Silva

Biomedicine and Animal Models in Research Collection

This report, produced jointly by the British Union for the Abolition of Vivisection and Compassion in World Farming, fills a number of significant gaps in the current debate about xenotransplantation.

In this report we also summarise the ethical and welfare issues concerning experiments on animals for xenotransplant research and their possible use as source animals for organs. Both these aspects are responsible for much pain and distress caused to many animals. We prefer the term “source animals” to “donor animals”, because animals do not choose to donate their organs for xenotransplantation.

The Creation Of Transgenic Animal “Models” For Human Genetic Disease, Bernard Rollin

Biomedicine and Animal Models in Research Collection

Transgenic animals will be created to study human genetic disease as soon as the technological capability exists to do so. Extant laws permit such animals to be created. The mindset of the research community makes it inevitable. It is also clear that such diseases can cause enormous amounts of pain and suffering. Responsible researchers need to explore all possible avenues for controlling such pain and suffering. Thus far the research community has not engaged this issue vis a vis animals. The development of methodologies for controlling pain and suffering is likely to be exportable to numerous areas of animal research, …